// Aim:Refer Example 9-3 for Problem Description 
// Given:
// poppet area:
A_poppet=0.75; //in^2
// hydraulic pressure:
p_hydraulic=1698; //psi
// full poppet stroke:
l_stroke=0.10; //in
// cracking pressure:
p_cracking=1.1*1132; //psi